package top.tagao.features_03_SteamApi;

import org.junit.jupiter.api.Test;
import top.tagao.features_02_References.Employee;
import top.tagao.features_02_References.EmployeeData;

import java.util.Arrays;
import java.util.List;
import java.util.stream.IntStream;
import java.util.stream.Stream;

/**
 * @author fu-xiao-liu
 * @Date 2022/3/20 14:37
 */
public class SteamApi_01_new {

    //创建 Stream方式一：通过集合
    @Test
    public void test1() {
        List<Employee> employees = EmployeeData.getEmployees();
        //default Stream<E> stream() : 返回一个顺序流
        Stream<Employee> stream = employees.stream();

        // default Stream<E> parallelStream() : 返回一个并行流
        Stream<Employee> parallelStream = employees.parallelStream();
    }

    //创建 Stream方式二：通过数组
    @Test
    public void test2() {
        int[] arr = new int[]{1, 2, 3, 4, 5, 6};
        //调用Arrays类的static <T> Stream<T> stream(T[] array): 返回一个流
        IntStream stream = Arrays.stream(arr);

        Employee e1 = new Employee(1001, "Tom");
        Employee e2 = new Employee(1002, "Jerry");
        Employee[] arr1 = new Employee[]{e1, e2};
        Stream<Employee> stream1 = Arrays.stream(arr1);
    }

    //创建 Stream方式三：通过Stream的of()
    @Test
    public void test3() {
        Stream<Integer> stream = Stream.of(1, 2, 3, 4, 5, 6);
    }

    //创建 Stream方式四：创建无限流
    @Test
    public void test4() {
        //迭代
        //public static<T> Stream<T> iterate(final T seed, final UnaryOperator<T> f)
        //遍历前10个偶数
        Stream.iterate(0,t -> t + 2).limit(10).forEach(System.out::println);

        //生成
        //public static<T> Stream<T> generate(Supplier<T> s)
        Stream.generate(Math::random).limit(10).forEach(System.out::println);
    }
}
